It’s the only CMS that runs on a classic AMP stack which is still the standard with cheap web hosters. And since everyone and their dog is using it, you can easily find support and ready-to-use plugins for almost anything.
In the car world, WordPress is your plain old petrol car that just runs, can easily be refuelled and you can get anything repaired at every other street corner. That’s why it is still so widespread.
I figured this when IKEA started throwing out their current model for £5 a pop. Judging by how fast their stock was gone, they‘ll show up on ebay for a hefty markup any time now…